Overbed table



Dec. 2, 1969 w. F. LA MAR ETAL OVERBED TABLE 2 Sheets-Sheet 1 Filed NOV. 24, 1967 INVENTORS William F. LaMar Fred Pruim BY M ATTORNEY.

w. F. LA MAR ET AL 3,481,286

OVERBED TABLE 2 Sheets-Sheet:

ATTORNEY Dec. 2, 1969 Filed Nov. 24, 196'? 5 O M m55= q r k 0 fl z/ .i 0 6 MM m 6 E F. m Cl 2 N O 4 m w@ F -l W 5 & MR 6 PM TH Y B M. w 5 0 iHAw 1 E El United States Patent U.S. Cl. 108-444 3 Claims ABSTRACT OF THE DISCLOSURE An overbed table is disclosed herein which has the top thereof spring biased upwardly and which may be adjustably positioned by the simple actuation of a single lever adjacent the top of the table and which is held in the adjusted position by a brake.

SUMMARY OF THE INVENTION This invention relates to an improved overbed table which is vertically adjustable and is provided with a novel and improved brake which is actuatable by the same lever utilized in raising and lowering the surface of the table. The brake provides a fail-safe means for locking the table in any vertical position, and can be easily released to allow vertical readjustment movement of the table, and yet will allow the surface of the table to support tremendous loads to a much greater extent than heretofore possible with any known type of overbed table brake locking positioning mechanism.

Other advantages and novel aspects of the invention will become apparent upon the following detailed description, in conjunction with the accompanying drawings wherein:

FIG. 1 is an elevation view of the improved overbed table showing the general construction thereof;

FIG. 2 is a partial sectional view of the upper portion of the improved overbed table;

FIG. 3 is a partial sectional view of the bottom portion of the improved overbed table;

FIG. 4 is a sectional view taken along line 4--4 of FIG. 2 showing the telescoping bottom and top portions of the improved overbed table;

FIG. 5 is a partial view of the brake mechanism of the improved overbed table; and

FIG. 6 is a plan view of the brake element of the adjustable brake mechanism.

Referring to the drawings, there is illustrated an improved overbed table structure (FIG. 1) which embodies invention and which is generally designated by the num eral 10. The overbed table generally includes a base 11, a top 12, and an interconnecting column portion generally designated by the numeral 13. The base 11 includes, among other things, a horizontal member 14 supported by fixed or movable casters 15. The top 12 includes, among other things, a horizontal surface 16 and a column supporting bracket 18. The column 13 includes generally two telescoping members and an adjustable brake release 20, 21 and 22 respectively.

The column 13, in particular, includes a tubular base extension generally designated by the numeral 20, which is rigidly secured to the horizontal member 14 (FIGS. 1 and 3), and which extends vertically upward therefrom. The column 13 also includes a tubular top extension 21 secured to the bracket 18 and extending vertically downwardly in spaced-telescopic relation over the tubular base extension 20. Further, the column 13 includes an adjustment make carriage assembly generally designated by the numeral 22 mainly contained within the tubular base 20 (FIGS. 1-5).

The tubular base extension 20 is provided with a shaft 3,481,286 Patented Dec. 2,1969

ICC

24 secured to a plate 25 of the base 11 (FIGS. 2, 3 and 5) and a top bracket 26 (FIG. 2) secured to the top thereof which holds the top of the shaft 24 in the position generally in the center of the base extension 20 (FIG 4). Rollers 27 are rotatably secured near the bottom of the top tubular extension 21. Similarly, a pair of rollers 28, having a thrust flange 29, are rotatably mounted on bearings 30 respectively secured to opposite sides of the lower portion of the extension generally adjacent the rollers 28 (FIGS. 2 and 4). A vertical rail 31 is provided on the outer surfaces of the lower tubular extension 20 between each of the rollers 27 and 28, which is adapted to laterally support the bottom portion of the top tubular extension 21 on the rollers 27 and 28 (FIG. 4). The thrust flanges 29 of the rollers 28 act to laterally support the top tubular extension 20 in the other direction.

The top of the top extension 21 is laterally supported on rollers 35 which are rotatably mounted on bearings 36. The bearings 36 are secured to angle brackets 37 which in turn are secured to the tubular base extension 20. The brackets 37 position the rollers 35 such that the rollers will respectively engage the inner corners of the top tubular extension 21 as shown (FIG. 2).

A negator spring 40 is rotatably supported on a shaft 41 (FIG. 2), which is secured at the ends thereof between the bottom tubular members extensions 38. The negator spring 40 is extended from the top portion of the top tubular member 21 downwardly along the right side (FIGS. 2 and 4) of the tubular top extension 21, and the bottom thereof is provided with an upwardly extending portion 42 which is retained by a bracket 43 secured to the bottom of the upper tubular extension 21 (FIG. 3). The negator spring 40 thereby extends from the top of the bottom tubular member 20 and the spring bracket 43 of the bottom of the top tubular extension 21, so as to urge the extension 21 upwardly against the force of gravity on the table to 12.

The brake adjustment assembly 22 is provided with a brake carriage 45, which is secured to the upper portion of the top extension 21 by a bolt or similar means 46, and extends downwardly into the bottom extension 20 (FIGS. 2, 3, and 5,) and terminates in lower and upper brake supporting platforms 47 and 48 generally perpendicular to and surrounding the shaft 24 (FIGS. 2, 3 and 5). When the table top is moved relative to the base, the brake adjustment assembly 22 will move therewith and thus the platform will move relative to the shaft 24 secured to the base 14. A resilient cushion 49 is provided around the shaft 24 on the member 25 to resiliently support the platform 47 when the table top is lowered to its lowermost position (FIG. 3).

A brake element 50 (FIGS. 2 and 3-6) is provided with a brake surface passage 51 therein through a downwardly extending brake portion 52 thereof and is mounted on the shaft 24 with the shaft 24 positioned in the aperture 51. The brake element is supported on a spring 53 which is partially positioned around the downwardly extending brake portion 52 and on the platform 47 so as to bias the brake element 50 upwardly. The brake element 50 is further provided with a clearance passage 54 concentric with the brake passage 51, and is further provided with a radially extending flange 55 having a relieved portion 56 adapted to slidably receive a pin 57 secured between the bottom and top platforms 47 and 48 parallel to the shaft 24 to guide the brake element 50. A frustoconical surface 58 is provided in the upper portion of the brake element 50 and is eccentric with respect to the shaft 24 and the brake surface 51 of the brake element .50 with the axis thereof displaced away from the axis of the shaft 24 and the relieved portion 56.

A tapered lock bearing 60 is slidably mounted on the shaft 24 and is rigidly secured to the upper platform 48.

The bearing 60 is provided with a downwardly extending frusto-conical surface 61, and is complemental in shape with respect to the frusto-conical surface 58 of the brake element 50, and is adapted to substantially engage the frusto-conical surface 58 of the brake element 50 as the brake element is normally urged into engagement therewith. Inasmuch as the frusto-conical surface 58 of the brake element 50 is eccentric with respect to the frustoconical surface 61 of the bearing 60, the brake element 50 will tend to rotate counterclockwise (FIGS. 3 and 5) when it engages the frusto-conical bearing surface 61 thereby causing the brake surface 51 of the brake element 50 to bind against the surface of the shaft 24 to prevent down movement of the bearing 60.

However, when the platform 48 is urged upwardly with the carriage 45 by similarly urging the table top 12 upwardly, the bearing 60 will be moved with respect to the brake element 50 thus releasing the binding-braking relationship therebetween as exerted through the element 50 against the shaft 24. Accordingly, the overbed table of this invention can be adjusted upwardly by merely applying an upward force against the table top 12, but will be prevented from downward movement by the braking action of a braking element 50 with respect to the shaft 24.

The brake release mechanism 23 is provided for selectively releasing the brake element 50 from braking engagement with the shaft 24 and includes generally a brake release arm pivot link 71 (FIGS. 2-5), vertical link 72, horizontal link 73 (FIG. 2) and release knob 74. The release arm 71 is U-shaped with a short leg 74 and a long leg 75 each pivotally connected to a downwardly extending U-shaped yoke 76 at 77 at the lower ends thereof.

The extremity of the long leg 75 of the release arm 71 is pivotally connected to the bottom of the vertical link 72 at 78 and a portion 79 interconnecting the legs 74 and 75 is positioned over the offset portion 55 on the right (FIGS. 2, 3, 4 and 5) of the brake element 50. The top of the link 72 is loosely secured to the horizontal link 73 at 79. The horizontal link 73 is provided with an elongated lateral aperture 80 which is adapted to receive a pin 81 at the right side of the top tubular extension 21 (FIG. 2).

Thus, the right end of the horizontal link 73 is pivotally secured to the right side of the member 21. The left side of the horizontal link 73 is secured to the knob 74 through a spacer 81 that extends through an opening 82 of the left side of the upper tubular extension 21. The link 73, and the knob 74 are urged downwardlyby the action of a spring 83 secured to the link 73 and in biased engagement with the bottom of the table top 12.

It should be noted that the knob 74 may be moved from the position shown (FIG. 2) to an upper position to cause the vertical link 72 to be likewise moved upwardly. When the link 72 is thus moved upwardly, the pivot link 71 will pivot clockwise about pivot 77 causing the interconnecting portion 79 thereof to engage the brake element flange 55 to pivot the brake element 50 counterclockwise, releasing the brake 50 from braking engagement with the shaft 24. By moving the knob 74 upwardly, the brake element 50 is released and the table top 12 can be lowered by applying a downward force thereon or by allowing the force of gravity to act thereon while the knob is retained in the up position.

The present invention thus provides an improved overbed table 10 whereby the top 12 thereof is adjustable vertically upward by simply applying an upward force to the table top itself, and is provided with a novel frustoconical camming brake which applies an extremely large actuating force to a braking element which in turn provides a much larger braking force than was heretofore possible with known types of overbed table brakes and yet allow easy release thereof, as well as allow upward movement of the table top by the application of a simple upward force thereon.

It is to be understood that the invention is not to be limited to the specific constructions and arrangements shown and described, as it will be understood to those skilled in the art that changes may be made without departing the principles of the invention.

What is claimed is:

1. An improved vertically adjustable overbed table comprising a base having a vertical tubular extension, a top having a vertical tubular extension telescopically movably mounted over said tubular base extension, means for urging said top upwardly to partially support the weight of said top, a vertical shaft secured to said base and extending upwardly within the base extension and said top extension, a brake carriage secured to said top and eX- tending downwardly into said tubular base extension, said brake carriage terminating in lower and upper brake sup porting platforms spaced longitudinally apart on said shaft and adjacent thereto, a lock bearing secured to said upper platform and slidably mounted on said shaft, said lock bearing having a frusto-conical portion extending concentrically along said shaft toward said lower platform, a lock element loosely mounted on said shaft and normally biased into engagement with said lock bearing, said lock element having a frusto-conioal surface extending eccentrically along said shaft and adapted to eccentrically engage a portion of said lock bearing frusto-conical surface for causing said lock member to be urged laterally to bind against said shaft to brake downward movement of said brake carriage with respect to said shaft, and brake release means for urging said lock member away from said lock bearing to release said downward braking thereof with respect to said shaft.

2. An improved vertically adjustable overbed table as defined in claim 1 wherein said lock bearing frustoconical surface is external and said lock element frustoconical surface is internal.

3. An improved vertically adjustable overbed table as defined in claim 2 wherein said brake release means includes a lever pivotally secured to said upper platform and wherein said lever is adapted to have one end thereof engage and urge said lock element downwardly away from said lock bearing when said lever is pivoted into engagement therewith, and manually operable linkage connected thereto and normally biased to pivot said lever away from engagement with said lock element for manually pivoting said lever into releasing engagement with said lock element.

References Cited UNITED STATES PATENTS 811,217 1/1906 Corey. 3,188,986 4/1962 La Vigne. 3,191,902 1/1965 Goller. 3,286,663 11/1966 Mann et a1. 248162 X 3,310,008 3/ 1967 Aleska et al. 3,314,384 4/1967 Mann et a1. 108-136 3,380,405 4/1968 Barecki et al 108136 FOREIGN PATENTS 1,086,361 10/1954 France.

JAMES T. MCCALL, Primary Examiner US. Cl. X.R. 

